Qsar Study of the Toxicity of Benzothiazolium Salts AgainstEuglena Gracilis: The Free-Wilson Approach

Abstract

The Free-Wilson QSAR model in the Fujita-Ban modification was used to calculate the quantitative substituent activity contributions to the toxicity against Euglena gracilis in a series of 91 benzothiazolium salts. An important increase of activity was found for R1 = styryl or SCH2C6H5 group and for R2 = propargyl or allyl group. The substituents on benzene ring also enhance the activity. The possible relations between structure of active groups and their electronic or physicochemical properties are discussed. By using the calculated values it is possible to predict toxicity for 1300 compounds. New compounds with assumed high or low toxicity are predicted.

Antibacterial activities, DFT and QSAR studies of quinazolinone compounds

“…The QSAR have frequently been used to determine the correlations between the biological activities and the physicochemical properties of various compounds [30,31]. The QSAR methods are well known to identify structural blocks responsible for high biological activity [32]. The QSAR study of all the investigated compounds have been carried out and presented in Table 4.…”

Free-Wilson-Type Analysis of Non-Additive Substituent Effects on THPB Dopamine Receptor Affinity Using Artificial Neural Networks

“…To recognize whether this unfavorable result was indeed due to non-additivity or simply due to large experimental errors in the activity data a``nonlinear Free-Wilson analysis'' was performed using an Arti®cial Neural Network (ANN) of the back-propagation type [11] and the same nine indicator variables of the previous FreeWilson analysis as independent variable input to the ANN. To the best of our knowledge a neural network analysis has been applied to a Free-Wilson structureybiological activity data set only by the group of Zahradnõ Âk et al [14,15], whereas several other investigators analyzed various physicochemical properties of chemicals by a similar approach [9,16,17].…”

Synthesis and study of new antimicrobial benzothiazoles substituted on heterocyclic ring

“…The original set of 91 compounds contained 4 compounds with Cl in position 4, seven compounds with 6-Cl, four compounds with 4-CH 3 and eight with 6-CH 3 . 4 The calculated Free-Wilson activity contributions of these substituents are not very high (6-Cl = 0.206; 6-CH 3 = 0.235; 4-CH 3 = 0.250; 4-Cl = 0.260). The biological activity of compounds substituted on heterocyclic ring is increased in all cases.…”

“…2,3 The bactericidal properties of 2-substituted benzothiazoles have been recognized for a long time, the most effective structures were recognized as 3-allyl and 3-propargyl benzothiazolium salts with pdialkylaminostyryl substituents. 4 This work is a part of the systematic study of biologically active benzothiazole derivatives. 4,5 Previously, these compounds have been tested against model organism Euglena gracilis as well as other microorganisms and QSAR study has been carried out.…”

“…4 This work is a part of the systematic study of biologically active benzothiazole derivatives. 4,5 Previously, these compounds have been tested against model organism Euglena gracilis as well as other microorganisms and QSAR study has been carried out. 6 A new series of benzothiazoles have been designed and synthesised.…”